The cross-section of p-i-n Si:H solar cells deposited by PECVD at 13.56 MHz on ZnO-covered glass substrates was studied by TEM and Raman spectroscopy. Two cells prepared under different conditions were compared. Independently of the deposition parameters, the i-layer of the SiH films was found to consist mostly of nanocrystallites agglomerated in filaments oriented along the growth direction, surrounded by amorphous material. No incubation layer for the crystallites was seen, and it was shown that the crystallization is not influenced by the Ag contact. No drastic difference in morphology was observed by TEM between the relatively high (6.1%) and low efficiency (2.9%) single-junction solar cells studied. However, Raman spectroscopy showed the high efficiency cell to be more uniform and have less amorphous material. © 2002 Elsevier Science B.V. All rights reserved.